In my coustom board,I use emmc/sd as boot source.but i don't use SDHC_CD_B pin.it always floating.my board is refer to ls1046ardb board.
Now I can boot from sd card ,but i can't boot from emmc.
why I can boot from sd? the SDHC_CD_B pin is floating And Why I can't boot from emmc,Is it because PBL has special regulations for this pin?
in spec,when use sdhc as boot source, SDHC_CD_B pin be serve as the SDHC_CD_B pin for the eSDHC controller. This happens automatically when the microSD card is selected as the boot source for the board.